The current dissertation investigates the association between personality (in the case of the current dissertation: intelligence and dispositional valuations) and people’s ability to understand each other’s thoughts and feelings (mutual understanding). If there is any association between a personality trait and a certain phenomenon, then the consequences of the underlying process should be most readily apparent in people with extreme values of this trait. Thus, it can be useful to focus on extreme groups in order to understand the mechanism behind such an association. Regarding the link between intelligence and mutual understanding, the following debate about intellectual giftedness, which appeared in the online version of the Dutch Volkskrant newspaper (in November 2001), is a case in point. One participant, who apparently had a critical view of gifted individuals, posted a comment stating that “[…] gifted people live ‘in their own world’.” He went on to say that “Often, the social isolation is even exacerbated by a lack of empathy for fellow human beings, which often gives rise to arrogance (people are stupid, cannot think, etc.)”. One reader, apparently someone with first-hand experience, reacted:

You have no idea what you are talking about. Being gifted is not about […] choosing deliberately to be socially awkward. Giftedness comes closer to trying your very best for years to participate in small-talk but just not being able to succeed. After every spontaneous effort, people look surprised and depreciate you as being a weirdo, nerd, or dork, just because you think the typical social conversation is too trivial to come up with an appropriate contribution. So that leaves only two options: Either you think three times how to say something in order to belong to the group, or you just keep quiet and remain silent in a corner. I hope you understand that a computer or a good book are a lot more pleasant than these two other options.

Of course, this discussion is dominated to a large degree by stereotypes and untested assumptions. Yet in a nutshell, it captures all the questions of the current dissertation. The first commentator (so it seems) addresses a so-called main effect: According to this individual, there exists a generally negative association between a person’s intelligence and his or her empathic skills. In defense, the second commentator points to the existence of dyadic effects, which are dependent on the interplay between two interaction partners. In his opinion, gifted people suffer from a mismatch between their interests and those of most other people. The current dissertation addresses these questions more systematically. In contrast to the opinion of the first commentator, a model by Simonton (1985) hypothesizes that intelligence is positively associated with the ability to understand other people. Like the second commentator, however, the model also assumes that between-person differences in intelligence limit the ability of the more intelligent person to make him- or herself understood. Putting this model to the test, it is first investigated whether intelligence and dispositional valuations exert a main effect on people’s ability to establish a sense of mutual understanding. Second, it is tested whether differences between interaction partners in terms of these traits influence their ability to communicate their thoughts and feelings. Third, the question is asked what the combined influence of main and dyadic effects is in an extreme group of intellectually gifted individuals.

Before I go on to address these questions, my thanks go out to many people and institutions. First of all, I wish to thank the Max Planck Institute for Human Development in Berlin and the Dutch Prins Bernhard Cultuurfonds for providing me with the necessary funding to complete this research. I am also indebted to Jacque Eccles and Alexandra Freund for commenting on earlier versions of this thesis, and to Susanne Scheibe who skillfully and conscientiously acted as its proof reader. Thanks also go to Alain May, who collected the data of Study 1.II for his master’s thesis, and to my former student assistants Benjamin Bornschein, Wenke Burde, and Katherina Flaig, who helped me in collecting and evaluating the data of Study 4. Also, I greatly benefited from conversations with my colleagues at the department of Personality Psychology at Humboldt University: Rainer Banse (now at the University of York), Judith Lehnart, Franz Neyer, Lars Penke, and Cornelia Wrzus. And of course, I do not want to forget the participants in my studies, who allowed me to analyze their responses to the many questions I asked them. Finally, I wish to thank my advisor Jens Asendorpf for his loyal support, his insightful comments on the products of my scholarship, and his inspiring guidance as a mentor.

I dedicate this work to Claudia, who put up with my long working hours and acted as an inexhaustible source of emotional support whenever I needed some.